Investigators said Wednesday that an ongoing family dispute led to the shootings, but they declined to give additional details.
The bodies of the five individuals were discovered Sunday in their single-story brick home in Bellville, a town of about 4,000 people 55 miles northwest of Houston.
Thomas was arrested about 3 a.m. Sunday after a homeowner pulled a gun on him after he broke into a vehicle and tried to break into a home 1 1/2 miles from where the murders took place.
